Non-linear analysis of disposable knee bracing

An approximate method is presented that can be used to determine the non-li near behaviour of a new structural bracing system called the 'Disposable Kn ee Bracing'. In this framing system, a special form of diagonal brace conne cted to a knee element instead of beam-column joint, is investigated. The d iagonal element provides lateral stiffness during moderate earthquakes. How ever, the knee element is designed to have three plastic joints for dissipa tion of the energy caused by strong earthquake. This article demonstrates t he transformation of a complex problem into a new, practical set of design charts and graphs. First, by studying of the elastic behaviour of the syste m, a suitable shape and angle for diagonal-knee bracing is proposed. Then, by use of the main graphs and charts designed accordingly, the dynamic resp onse of this model is properly investigated. Finally, the correctness of th e results is ascertained, using an example problem. (C) 2000 Elsevier Scien ce Ltd. All rights reserved.